1. Field of the Invention
The present invention relates to aldimine based coating compositions, aldimine based pigment dispersions, and coating compositions containing the aldimine dispersions.
2. Description of the Prior Art
It is known in the art to use dialdimines, diketimines and hindered diamines to modify polyol compositions to decrease overall viscosity of a polyol composition, while maintaining and improving network building and overall physical properties. This is disclosed in Mormile et al. U.S. Pat. No. 5,214,086.
It is known in the art to utilize coating compositions comprising aldimines and isocyanates containing uretdione functionality. This is disclosed in Patent GB 1, 064, 841, to Haggis. However, coating compositions comprising aldimines and uretdiones exhibit problems of short pot life, due to moisture in the coating system introduced by solvents, impurities in the system, hydration of pigments or fillers and atmospheric moisture. The presence of moisture in the system requires introduction of moisture scavengers that slow down dry time. It is an object of the present invention to provide coating compositions containing aldimine and uretdione isocyanates with improved pot life and to provide a method for improving the pot life of these coating compositions. It is a further object of the invention to improve dry or cure times for these coating compositions.
An additional object of the present invention is to provide pigment or filler dispersions comprising aldimine for use in a coating composition including isocyanate having uretdione functionality and coating compositions comprising these pigment dispersions.